Piezo electric crystal apparatus



NOV 8, 1932. CRQSSLEY 1,886,792

PIEZO ELECTRIC CRYSTAL APPARATUS Filed Nov. 24, 1928 1:. Eval 4 Z3 /4 ll n 1 i 1 i INVENTQR. '1 n iii/"942! @wsmZe R-WAL A TTORNEY Patented Nov. 8, 1932 UNITED STATES PATENT OFFICE- ALFRED CROSSLEY, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO WIRED RADIO, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE PIEZO ELECTRIC CRYSTAL APPARATUS Application filed November 24, 1928.

My invention relates broadly to piezo electric crystal apparatus and more particularly to a construction of holder for apiezo electric crystal element.

One of the objects of my invention is to provide a practical construction of piezo electric crystal holder in which the piezo electric crystal element is free to vibrate without restriction and is so mounted as to deliver the maximum piezo electric effect to a control circuit.

Another object of my invention is to pro vide a mounting for a piezo electric crystal element in which the frictional contact between the housing of the crystal and the faces of the crystal is reduced to a minimum for obtaining the maximum piezo electr1c effect from the crystal.

Still another object of my invention is to provide a supporting structure. for a p ezo electric crystal element wherein the piezo electric crystal is centered within an enclos ng container by means of cord members wh ch embrace the edges of the crystal for locating the crystal in a plane extending substantlally central of the container and spaced from the side walls of the container for allowing the maximum piezo electric effect to be obtained from the crystal with minimum losses to the friction.

A further object of my invention is to provide a construction of mounting for a p ezo electric crystal element by which the piezo electric crystal element may be supported in a plane extending substantially perpendicular to the top and bottom walls of an enclosing casing and maintained in position in a manner free to vibrate for delivering the maximum piezo electric effect to terminals exterior of the casing.

Other and further objects of my invention reside in the construction of piezo electric crystal apparatus described more fully in the specification hereinafter following and set forth in the accompanying drawing in which:

Figure 1 is a plan view of the interior arrangement of the piezo electric crystal apparatus, the top of the casing being broken away; Fig. 2 is a side elevation of the p1exo electric crystal apparatus shown partially in Serial No. 321,694.

cross-section; Fig. 3 is a cross-sectional view taken through the piezo electric crystal apparatus of Fig. 1 on line 33 thereof; and Fig. 4 is a lateral cross-sectional View taken through the piezo electric crystal apparatus on line ti thereof.

In the piezo electric crystal mounting of my present invention, I utilize a piezo electric crystal the faces of which are covered with a conductive material which is closely united with the faces of the crystal, providing a metallic covering of film over the area of the faces of the crystal. Contact is established with the conductive film on the faces of the crystal by means of connectors which establish a wiping contact with the film. The crystal in the mounting of my present invention is positioned in a plane which extends in a direction coincident with the axis of the housing. Cord members are stretched in opposite directions laterally across the housing for malntaining the piezo electric crystal element in central position within the housing substantially free of frictional contact with the housing, except for a pair of substantially non-frictional supporting contacts.

The structure of my invention has been found to be extremely practical in its operation in the sustaining of electrical oscillations of extremely high frequency.

The arrangements of parts will now be pointed out in more detail by applying identifying reference characters to the different parts of the housing. Reference character 1 designates the bottom closure of the insulatmg housing 3. A pair of laterally extending rlbs 2 are provided on the base 1. The ribs 2 are substantially in the shape of the inverted V members terminating in knife edges. The piezo electric crystal element 18 rests upon and is supported by the laterally extendmg ribs 2 as will be more fully hereinafter described. The housing 3 is provided with an insulated cover 4 establishing a substantially hermetically sealed enclosure for the piezo electric crystal element. Gaskets 25 provide an air tight seal at the top and bottom of the casing. Terminals 5 and 6 extend outwardly from the sides of the casing 3 and are secured by screw members 21 and 22 interiorly of the casing 3. Fine wire brushes l9 and 20 extend from the screw meinbers 21 and 22 and establish wiping contacts with the metal films on each face of the piezo electric crystal element 18. The line wire brushes l9 and 20 have that amount of resiliency as will introduce the required forces for setting up sufficient pressure to. establish good contact with the faces of the crystal. In order to maintain the piezo electric crystal element for position within the housing, I provide an arrangement of laterally extending cords shown at 7-8910 and at 1e17 and at 12-13. The cord l4e-17 extends laterally through the side walls of the container 3 adjacent the upper edge of the crystal 18. The cord 12-13 extends in planes coincident with the planes which contain the cord 14117 and in a position adjacent the lower edge of the crystal 18. The cord 78910 extends in a plane which is laterally between the planes which include the'aforementioned cords and in positions where the cord embraces the opposite edges of the piezo electric crystal for maintaining the crystal in a central vertical plane within the housing. relatively flexible and do not restrain vibration of the crystal but permit the crystal to vibrate substantially free and with minimum friction with respect to the walls of the housing, inasmuch as the crystal contacts with the housing only at the knife edges 2 of the laterally ext-ending ribs. 1

While I have described my invention i certain preferred embodiments, I desire that it be understood that modifications may be made and that no limitations upon my invention are intended except as imposed by the scope of the appended claims.

a What I claim as new and desire to secure by Letters Patent of the United States is as follows: I

1. Piezo electric crystal apparatus comprising an insulated housing, means for supporting a piezo electric crystal element within said housing, a plurality of textile cords extending laterally and laced through the side walls of the housing for maintaining a piezo electric crystal element in position, and means including flexible stranded or laminated conductors for establishing electrical contact with the faces of the piezo electric crystal element.

2. Piezo electric crystal apparatus comprising an insulated housing, a piezo electric crystal element erected in a vertical position within said housing, a plurality of parallelly and rectangularly disposed cord members extending laterally and laced through the side walls of the housing and engaging the opposite edges and opposite faces of said piezo electric crystal element for maintaining the piezo electric crystal element in a vertlcal position within the housing, and means 1ncluding flexible conductors and conductors The cords are in contact with the body of said crystal element for establishing electrical connection with opposite faces of the piezo electric crystal element.

3. Piezo electric crystal apparatus comprising an insulated housing, a piezo electric crystal element having metallic coated faces and mounted within said housing, a plurality of cord members extending laterally through the side walls of said housing and engaging the opposite edges and faces of said piezo electric crystal element, flexible contact means extending from the interior side walls of said housing. and wiping the metallic coated faces of the piezo electric crystal element for establishing electrical connection therewith.

4. Piezo electric crystal apparatus comprising a casing, a pair of laterally extending internal ribs of sharp edged formation on the bot-tom of said casing, a piezo electric crystal element supported on said ribs, a plurality of cord members each engaging one of the edges or faces of said piezo electric crystal element and maintaining said element in a position free to vibrate within said casing.

5. Piezo electric crystal apparatus comprising an insulated hermetically sealed casing, means on the interior of the base of said casing supporting a'piezo electric crystal element, a plurality of cord members extending laterally through said casing and embracing the faces and edges of the piezo electric crystal element therein, and resilient means mounted on the walls of said casing and electrically connected with the faces of the piezo electric crystal element.

6. Piezo electric crystal apparatus com prising a hermetically sealed casing, a pair of rib members of sharp edged formation extending laterally across the bottom of said casing, a piezo electric crystal element supported by said rib members, a cord member embracing opposite faces of said piezo electric crystal element, and a separate cord member embracing the opposite ends of said piezo electric crystal element, said cord members being secured through the side walls of said casing, whereby said piezo electric crystal element is maintained in a central position with respect to the axis through said casing, and means including flexible stranded or laminated conductors projecting from the inner walls of said casing for establishing electrical connection with the faces of said piezo electric crystal element and for providing substantially undamped vibration of said crystal element.

7. A piezo-electric apparatus comprising a piezo-electric element, an encasing holder for said element, electrodes for and in contact with said element, means including knife-edged members within said holder and on the base thereof for supporting said element, and means including a plurality of cords stretched from wall to wall. of said holder and in a rectilinear manner alongside respective faces and edges of said element for positioning said element within said holder.

8. The invention set forth in claim 7 comprising terminals extending outwardly and oppositely from said holder and electrical connections including flexible brushes between said terminals and said electrodes.

9. A piezo-electric apparatus comprising a piezo-electric element, a container and electrodes therefor, means including knife-edged members of insulating material mounted within said container for supporting said piezo-element, and means including a plurality of retaining members laced through the walls of said container and stretched in a rectilinear manner alongside the faces and edges of said element for positioning the same within said container.

ALFRED CROSSLEY. 

